Youcef Ouazir - Academia.edu (original) (raw)

Papers by Youcef Ouazir

International journal of applied electromagnetics and mechanics, Jun 3, 2024

HAL (Le Centre pour la Communication Scientifique Directe), May 11, 2008

The air-gap interface coupling method is developed to simulate the rotor movement with time-stepp... more The air-gap interface coupling method is developed to simulate the rotor movement with time-stepping finite element (TSFE) method for the computation of transient operation of induction motors. The use of Fourier decomposition of magnetic vector potential on the coupling interface leads to the consideration of only the first or just significant space harmonics in FE computation. In this way, the study is focused on the reduction of computation time in the transient state analysis of induction motor. The obtained results are validated through measurements.

HAL (Le Centre pour la Communication Scientifique Directe), 2006

ABSTRACT A method for coupling the stator and rotor fields of induction motors in time harmonic f... more ABSTRACT A method for coupling the stator and rotor fields of induction motors in time harmonic finite element (FE) analysis with consideration of space harmonics is presented. The coupling scheme is derived from Fourier series of the magnetic vector potential at air-gap interface conditions. A transformation technique is used to introduce the coupling scheme in the saturated time harmonic FEs model coupled to the electrical circuits. The obtained results are compared to experiments in critical situations

IEEE Transactions on Applied Superconductivity, Aug 1, 2011

This paper presents a new structure of an induction heater for aluminium billets. The device cons... more This paper presents a new structure of an induction heater for aluminium billets. The device consists in using a strong DC magnetic field created by a superconducting inductor in which the conducting billet is actuated by a linear motion at a constant velocity. The analysis, based on the analytical model for the magnetic field in the billet, has been developed, and then the eddy currents and induced heating power have been evaluated. The analytical results are compared to those issued from a finite element software (COMSOL). The magneto thermal analysis shows that the temperature profile in the billet is homogenous.

IEEE Transactions on Magnetics, Mar 1, 2016

An electromagnetic model is proposed to compute translational motion eddy current in a conductive... more An electromagnetic model is proposed to compute translational motion eddy current in a conductive plate. The eddy currents are due to the movement of the plate in a dc magnetic field created by a PM inductor. Firstly, the magnetic field due to the PMs is computed in 3D where the iron yokes influence is considered thanks to the method of images. Then, the motional eddy currents are computed such that the edge effects are correctly taken into account through an iterative procedure which uses magnetic images. The computations are very fast and the obtained results are close to those issued from 3D FE method and from experiments.

European Physical Journal-applied Physics, 2022

A new 2D-hybrid model in cylindrical coordinates intended for the study of a transient magnetothe... more A new 2D-hybrid model in cylindrical coordinates intended for the study of a transient magnetothermal coupled problem is proposed. This model is used to evaluate the spatiotemporal distribution of temperature in rotating aluminum billets heated by permanent magnets induction-heating device (PMIHD). The proposed hybrid model consists of coupling an exact analytical solution of the 2D magneto-harmonic field to a 2D transient thermal analysis where the temperature dependence of electrical and thermal physical properties of the heated billet is considered. Based on the separation variables technique, the analytical solution of magneto-harmonic problem serves to evaluate the induced current and the resulting power density loss distribution in the nonmagnetic billet. Furthermore, the 2D transient thermal analysis, based on the lumped thermal network model, is developed in radial and axial directions of the heated billet. In order to validate the 2D hybrid magneto-thermal model, the performances of the studied PMIHD are compared with those obtained with Finite Element Method (FEM).

2022 IEEE International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM), Oct 26, 2022

IEEE Transactions on Magnetics

2022 2nd International Conference on Advanced Electrical Engineering (ICAEE)

The XIX International Conference on Electrical Machines - ICEM 2010, 2010

The current filaments (CFM) and the finite elements (FEM) models for analyzing Tubular Linear Ind... more The current filaments (CFM) and the finite elements (FEM) models for analyzing Tubular Linear Induction Motor (TLIM) performances are presented. The governing equations of CFM model can be reduced to the ordinary differential equations that can be solved by numerical method and it is easy to program. A 2D time harmonic finite elements analysis of the motor is used to validate the current filaments model. In order to analyze the electromagnetic performances of the motor, the two models are used to computing the electrical parameters, and the locked rotor and transient operations. A laboratory prototype of a tubular induction motor has been built for experimental study.

2014 International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM), 2014

In this work, we propose two approaches based on the theory of transmission lines to model the di... more In this work, we propose two approaches based on the theory of transmission lines to model the direct impact of lightning wave on a guard cable. The first consist to solving the propagation voltage equation in 2D by FDTD (Finite Difference Time Domain). We show the theoretical developments leading to the propagation equation in scalar potential, its finite difference discretization and the resulting linear algebraic equations. The second approach is based on solving the system of equations in time of transmission lines FDTD. The distributions of the potential and current are obtained.

This paper presents a 3D nonlinear reluctance network for modeling a superconducting synchronous ... more This paper presents a 3D nonlinear reluctance network for modeling a superconducting synchronous machine. The model can handle the strong saturation of the ferromagnetic materials due to the high magnetic field produced by the superconducting coils. The model is validated through 3D FEM computations and measurements.

Progress In Electromagnetics Research B

This paper aims to develop a new 3D analytical model devoted to the study of nonlinear transient ... more This paper aims to develop a new 3D analytical model devoted to the study of nonlinear transient magneto-thermal coupled problems in permanent magnet transverse flux induction heating device (PMTFIHD). Firstly, a 3D analytical solution of magneto-dynamic field problem taking into account the transverse edge effect in the workpiece is derived using variables' separation technique. This transverse edge effect allows determining the exact resulting heating power density, which is the heat source of the transient thermal problem in the work-piece. Secondly, the 3D transient analytical solution of the temperature distribution is obtained by combining variables' separation technique and Green's function method. Then, the previous models are exploited in a transient simulations procedure of the magneto-thermal process allowing the nonlinear physical properties of the part to be taking into account. Finally, the performances of the studied PMTFIHD will be calculated, in order to validate the developed 3D coupled models. The simulation results from the developed models are validated with those obtained by the finite element method and the experimental results.

2018 International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM), 2018

This paper presents a three dimensional (3D) analytical model to compute the electromagnetic torq... more This paper presents a three dimensional (3D) analytical model to compute the electromagnetic torque of axial magnetic coupling with rectangular-shaped permanent magnets (PM’s). First, an analytical 3D model in Cartesian Coordinates for calculating the magnetic field distribution in magnetic coupling with sector PM’s is developed. Then, we approximate the rectangular shape of PM with sector-shaped having the same area and thickness. The electromagnetic torque is computed using Maxwell’s stress tensor. The model’s validity has been verified by comparing the results calculated by the analytical model with those obtained from the 3D finite element method and measurements

2019 19th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering (ISEF), 2019

In this paper we present an electromagnetic model to compute translational motion eddy current in... more In this paper we present an electromagnetic model to compute translational motion eddy current in a conductive plate of an induction heater. The movement of the plate in a dc magnetic field created by a PM inductor generates induced currents that are at the origin of a heating power by Joule effect. The magnetic field expressions due to the PMs is obtained by solving the three dimensional Maxwell equations by the method of separation of variables, using a magnetic scalar potential formulation and a magnetic field strength formulation. The motional eddy currents are computed and the finite length extremity effects are taken into account using the image’s method. The proposed model takes into account the reaction field due to induced currents. The obtained results are close to those obtained from the 3D FE simulations and experiments.

2018 International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM), 2018

This paper presents a simple and accurate 3D analytical expressions to compute the force and torq... more This paper presents a simple and accurate 3D analytical expressions to compute the force and torque of an axial flux magnetic couplings (AFMC) based on the equivalent magnetic charges and the images method. The proposed model is formulated and solved in a 3D Cartesian coordinate system by considering the assumption of linearization around the mean radius. Firstly, the magnetic flux density due to the cubic permanent magnets (PM), of one side of the magnetic coupling, is computed in 3D considering the magnetic end effects where the iron yokes influence is considered thanks to the images method. Secondly, the force and the torque among the magnets located in the opposite sides are obtained using the analogy between the electrostatic and magnetostatic forces. The derived analytical expressions depend directly on the geometrical and physical parameters of the AFMC. The analytical results are compared to those obtained with finite element simulation and experimental measurements.

Physica C: Superconductivity and its Applications, 2018

In this paper a new superconducting inductor topology intended for synchronous machine is present... more In this paper a new superconducting inductor topology intended for synchronous machine is presented. The studied machine has a standard 3-phase armature and a new kind of 2-poles inductor (claw-pole structure) excited by two coaxial superconducting coils. The air-gap spatial variation of the radial flux density is obtained by inserting a superconducting bulk which deviates the magnetic field due to the coils. The complex geometry of this inductor usually needs 3D finite elements (FEM) for its analysis. However, to avoid a long computational time inherent to 3D FEM, we propose in this work an alternative modeling which uses a 3D meshed reluctance network. The results obtained with the developed model are compared to 3D FEM computations as well as to measurements carried out on a laboratory prototype. Finally, a 3D FEM study of the shielding properties of the superconducting screen demonstrates the suitability of using a diamagnetic-like model of the superconducting screen.

IEEE Transactions on Magnetics, 2016

An electromagnetic model is proposed to compute translational motion eddy current in a conductive... more An electromagnetic model is proposed to compute translational motion eddy current in a conductive plate. The eddy currents are due to the movement of the plate in a dc magnetic field created by a PM inductor. Firstly, the magnetic field due to the PMs is computed in 3D where the iron yokes influence is considered thanks to the method of images. Then, the motional eddy currents are computed such that the edge effects are correctly taken into account through an iterative procedure which uses magnetic images. The computations are very fast and the obtained results are close to those issued from 3D FE method and from experiments.

International journal of applied electromagnetics and mechanics, Jun 3, 2024

HAL (Le Centre pour la Communication Scientifique Directe), May 11, 2008

The air-gap interface coupling method is developed to simulate the rotor movement with time-stepp... more The air-gap interface coupling method is developed to simulate the rotor movement with time-stepping finite element (TSFE) method for the computation of transient operation of induction motors. The use of Fourier decomposition of magnetic vector potential on the coupling interface leads to the consideration of only the first or just significant space harmonics in FE computation. In this way, the study is focused on the reduction of computation time in the transient state analysis of induction motor. The obtained results are validated through measurements.

HAL (Le Centre pour la Communication Scientifique Directe), 2006

ABSTRACT A method for coupling the stator and rotor fields of induction motors in time harmonic f... more ABSTRACT A method for coupling the stator and rotor fields of induction motors in time harmonic finite element (FE) analysis with consideration of space harmonics is presented. The coupling scheme is derived from Fourier series of the magnetic vector potential at air-gap interface conditions. A transformation technique is used to introduce the coupling scheme in the saturated time harmonic FEs model coupled to the electrical circuits. The obtained results are compared to experiments in critical situations

IEEE Transactions on Applied Superconductivity, Aug 1, 2011

This paper presents a new structure of an induction heater for aluminium billets. The device cons... more This paper presents a new structure of an induction heater for aluminium billets. The device consists in using a strong DC magnetic field created by a superconducting inductor in which the conducting billet is actuated by a linear motion at a constant velocity. The analysis, based on the analytical model for the magnetic field in the billet, has been developed, and then the eddy currents and induced heating power have been evaluated. The analytical results are compared to those issued from a finite element software (COMSOL). The magneto thermal analysis shows that the temperature profile in the billet is homogenous.

IEEE Transactions on Magnetics, Mar 1, 2016

An electromagnetic model is proposed to compute translational motion eddy current in a conductive... more An electromagnetic model is proposed to compute translational motion eddy current in a conductive plate. The eddy currents are due to the movement of the plate in a dc magnetic field created by a PM inductor. Firstly, the magnetic field due to the PMs is computed in 3D where the iron yokes influence is considered thanks to the method of images. Then, the motional eddy currents are computed such that the edge effects are correctly taken into account through an iterative procedure which uses magnetic images. The computations are very fast and the obtained results are close to those issued from 3D FE method and from experiments.

European Physical Journal-applied Physics, 2022

A new 2D-hybrid model in cylindrical coordinates intended for the study of a transient magnetothe... more A new 2D-hybrid model in cylindrical coordinates intended for the study of a transient magnetothermal coupled problem is proposed. This model is used to evaluate the spatiotemporal distribution of temperature in rotating aluminum billets heated by permanent magnets induction-heating device (PMIHD). The proposed hybrid model consists of coupling an exact analytical solution of the 2D magneto-harmonic field to a 2D transient thermal analysis where the temperature dependence of electrical and thermal physical properties of the heated billet is considered. Based on the separation variables technique, the analytical solution of magneto-harmonic problem serves to evaluate the induced current and the resulting power density loss distribution in the nonmagnetic billet. Furthermore, the 2D transient thermal analysis, based on the lumped thermal network model, is developed in radial and axial directions of the heated billet. In order to validate the 2D hybrid magneto-thermal model, the performances of the studied PMIHD are compared with those obtained with Finite Element Method (FEM).

2022 IEEE International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM), Oct 26, 2022

IEEE Transactions on Magnetics

2022 2nd International Conference on Advanced Electrical Engineering (ICAEE)

The XIX International Conference on Electrical Machines - ICEM 2010, 2010

The current filaments (CFM) and the finite elements (FEM) models for analyzing Tubular Linear Ind... more The current filaments (CFM) and the finite elements (FEM) models for analyzing Tubular Linear Induction Motor (TLIM) performances are presented. The governing equations of CFM model can be reduced to the ordinary differential equations that can be solved by numerical method and it is easy to program. A 2D time harmonic finite elements analysis of the motor is used to validate the current filaments model. In order to analyze the electromagnetic performances of the motor, the two models are used to computing the electrical parameters, and the locked rotor and transient operations. A laboratory prototype of a tubular induction motor has been built for experimental study.

2014 International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM), 2014

In this work, we propose two approaches based on the theory of transmission lines to model the di... more In this work, we propose two approaches based on the theory of transmission lines to model the direct impact of lightning wave on a guard cable. The first consist to solving the propagation voltage equation in 2D by FDTD (Finite Difference Time Domain). We show the theoretical developments leading to the propagation equation in scalar potential, its finite difference discretization and the resulting linear algebraic equations. The second approach is based on solving the system of equations in time of transmission lines FDTD. The distributions of the potential and current are obtained.

This paper presents a 3D nonlinear reluctance network for modeling a superconducting synchronous ... more This paper presents a 3D nonlinear reluctance network for modeling a superconducting synchronous machine. The model can handle the strong saturation of the ferromagnetic materials due to the high magnetic field produced by the superconducting coils. The model is validated through 3D FEM computations and measurements.

Progress In Electromagnetics Research B

This paper aims to develop a new 3D analytical model devoted to the study of nonlinear transient ... more This paper aims to develop a new 3D analytical model devoted to the study of nonlinear transient magneto-thermal coupled problems in permanent magnet transverse flux induction heating device (PMTFIHD). Firstly, a 3D analytical solution of magneto-dynamic field problem taking into account the transverse edge effect in the workpiece is derived using variables' separation technique. This transverse edge effect allows determining the exact resulting heating power density, which is the heat source of the transient thermal problem in the work-piece. Secondly, the 3D transient analytical solution of the temperature distribution is obtained by combining variables' separation technique and Green's function method. Then, the previous models are exploited in a transient simulations procedure of the magneto-thermal process allowing the nonlinear physical properties of the part to be taking into account. Finally, the performances of the studied PMTFIHD will be calculated, in order to validate the developed 3D coupled models. The simulation results from the developed models are validated with those obtained by the finite element method and the experimental results.

2018 International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM), 2018

This paper presents a three dimensional (3D) analytical model to compute the electromagnetic torq... more This paper presents a three dimensional (3D) analytical model to compute the electromagnetic torque of axial magnetic coupling with rectangular-shaped permanent magnets (PM’s). First, an analytical 3D model in Cartesian Coordinates for calculating the magnetic field distribution in magnetic coupling with sector PM’s is developed. Then, we approximate the rectangular shape of PM with sector-shaped having the same area and thickness. The electromagnetic torque is computed using Maxwell’s stress tensor. The model’s validity has been verified by comparing the results calculated by the analytical model with those obtained from the 3D finite element method and measurements

2019 19th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering (ISEF), 2019

In this paper we present an electromagnetic model to compute translational motion eddy current in... more In this paper we present an electromagnetic model to compute translational motion eddy current in a conductive plate of an induction heater. The movement of the plate in a dc magnetic field created by a PM inductor generates induced currents that are at the origin of a heating power by Joule effect. The magnetic field expressions due to the PMs is obtained by solving the three dimensional Maxwell equations by the method of separation of variables, using a magnetic scalar potential formulation and a magnetic field strength formulation. The motional eddy currents are computed and the finite length extremity effects are taken into account using the image’s method. The proposed model takes into account the reaction field due to induced currents. The obtained results are close to those obtained from the 3D FE simulations and experiments.

2018 International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM), 2018

This paper presents a simple and accurate 3D analytical expressions to compute the force and torq... more This paper presents a simple and accurate 3D analytical expressions to compute the force and torque of an axial flux magnetic couplings (AFMC) based on the equivalent magnetic charges and the images method. The proposed model is formulated and solved in a 3D Cartesian coordinate system by considering the assumption of linearization around the mean radius. Firstly, the magnetic flux density due to the cubic permanent magnets (PM), of one side of the magnetic coupling, is computed in 3D considering the magnetic end effects where the iron yokes influence is considered thanks to the images method. Secondly, the force and the torque among the magnets located in the opposite sides are obtained using the analogy between the electrostatic and magnetostatic forces. The derived analytical expressions depend directly on the geometrical and physical parameters of the AFMC. The analytical results are compared to those obtained with finite element simulation and experimental measurements.

Physica C: Superconductivity and its Applications, 2018

In this paper a new superconducting inductor topology intended for synchronous machine is present... more In this paper a new superconducting inductor topology intended for synchronous machine is presented. The studied machine has a standard 3-phase armature and a new kind of 2-poles inductor (claw-pole structure) excited by two coaxial superconducting coils. The air-gap spatial variation of the radial flux density is obtained by inserting a superconducting bulk which deviates the magnetic field due to the coils. The complex geometry of this inductor usually needs 3D finite elements (FEM) for its analysis. However, to avoid a long computational time inherent to 3D FEM, we propose in this work an alternative modeling which uses a 3D meshed reluctance network. The results obtained with the developed model are compared to 3D FEM computations as well as to measurements carried out on a laboratory prototype. Finally, a 3D FEM study of the shielding properties of the superconducting screen demonstrates the suitability of using a diamagnetic-like model of the superconducting screen.

IEEE Transactions on Magnetics, 2016

An electromagnetic model is proposed to compute translational motion eddy current in a conductive... more An electromagnetic model is proposed to compute translational motion eddy current in a conductive plate. The eddy currents are due to the movement of the plate in a dc magnetic field created by a PM inductor. Firstly, the magnetic field due to the PMs is computed in 3D where the iron yokes influence is considered thanks to the method of images. Then, the motional eddy currents are computed such that the edge effects are correctly taken into account through an iterative procedure which uses magnetic images. The computations are very fast and the obtained results are close to those issued from 3D FE method and from experiments.